M103

M103 from VAO, Webster, NY
© Billy Vazquez 2011

A young open cluster in the constellation Cassiopeia. But how young is young, that is the question?  The age of this open cluster was estimated to be around 16 million years at a distance of 2900 parsec (Sanner et al., 1999).    The Solar System is roughly 4.5 billion years old.  If we use the age of our solar system and compare it to the stars in this cluster we come to the conclusion that the cluster is younger by 3 orders of magnitude.

M103 from VAO, Webster, NY
© Billy Vazquez 2011

How do we know which stars in the field of view are part of the cluster?    For that, we study the proper motion of the stars, which is the angular displacement over time with respect to the barycenter of the solar system.  All stars that belong to the cluster will have roughly the same proper motion. This indicates that the stars are gravitationally bound and traverse the Galaxy as a unit.

The images of M103 shown were taken using a Johnson V band filter with VAO's 12" SCT @ f/6.3.  They are 36x60 sec exposures co-added in Maxim DL for a total exposure time of 36 minutes.  The imgages were dark and flat subtracted but no further image processing performed other than the color inversion of the second image.